Rio Olympics: Grandmother is champion swimmer's biggest fan

Is there any greater supporter than a big-hearted grandmother?

When it comes to British swimming superstar Adam Peaty, the answer is an emphatic no.

The reigning world champion turned the 100m men's breaststroke final into a race against the clock when he crushed both the field and his own world record to win Great Britain's first gold medal at the Rio Olympics.

But the deafening roar inside the Olympic Aquatics Stadium was turned to a low muffle in the lounge room of Peaty's proud grandmother, Mavis.

Shaking a flag of the Union Jack and shouting encouragement as she watches the race on her television, Mavis erupts with a loud 'YEESSSSS' as Peaty again leaves his marks on the record books.

"Oh he's done it!" Mavis cries.

"He's the world champion and the Olympic champion and European champion and the Commonwealth champion.

"He's got all four."